Digital Commons Network^™

Tools For Visualizing And Analyzing Fourier Space Sampling In Cryo-Em, Philip R Baldwin, Dmitry Lyumkis

Faculty, Staff and Students Publications

A complete understanding of how an orientation distribution contributes to a cryo-EM reconstruction remains lacking. It is necessary to begin critically assessing the set of views to gain an understanding of its effect on experimental reconstructions. Toward that end, we recently suggested that the type of orientation distribution may alter resolution measures in a systematic manner. We introduced the sampling compensation factor (SCF), which incorporates how the collection geometry might change the spectral signal-to-noise ratio (SSNR), irrespective of the other experimental aspects. We show here that knowledge of the sampling restricted to spherical surfaces of sufficiently large radii in Fourier …

On The Application, Reporting, And Sharing Of In Silico Simulations For Genetic Studies, Kaleigh Riggs, Huann-Sheng Chen, Melissa Rotunno, Bing Li, Naoko I Simonds, Leah E Mechanic, Bo Peng

Faculty, Staff and Students Publications

In silico simulations play an indispensable role in the development and application of statistical models and methods for genetic studies. Simulation tools allow for the evaluation of methods and investigation of models in a controlled manner. With the growing popularity of evolutionary models and simulation-based statistical methods, genetic simulations have been applied to a wide variety of research disciplines such as population genetics, evolutionary genetics, genetic epidemiology, ecology, and conservation biology. In this review, we surveyed 1409 articles from five journals that publish on major application areas of genetic simulations. We identified 432 papers in which genetic simulations were used …

Fusobacteriumnucleatum Adheres To Clostridioides Difficile Via The Radd Adhesin To Enhance Biofilm Formation In Intestinal Mucus, Melinda A Engevik, Heather A Danhof, Jennifer Auchtung, Bradley T Endres, Wenly Ruan, Eugénie Bassères, Amy C Engevik, Qinglong Wu, Maribeth Nicholson, Ruth Ann Luna, Kevin W Garey, Sue E Crawford, Mary K Estes, Renate Lux, Mary Beth Yacyshyn, Bruce Yacyshyn, Tor Savidge, Robert A Britton, James Versalovic

Faculty, Staff and Students Publications

Background:

Although Clostridioides difficile infection (CDI) is known to involve the disruption of the gut microbiota, little is understood regarding how mucus-associated microbes interact with C. difficile. We hypothesized that select mucus-associated bacteria would promote C. difficile colonization and biofilm formation.

Methods/Results:

To create a model of the human intestinal mucus layer and gut microbiota, we used bioreactors inoculated with healthy human feces, treated with clindamycin and infected with C. difficile with the addition of human MUC2-coated coverslips. C. difficile was found to colonize and form biofilms on MUC2-coated coverslips and 16S rRNA sequencing revealed a unique biofilm profile …

Testosterone Therapy And Bone Quality In Men With Diabetes And Hypogonadism: Study Design And Protocol, Vittoria Russo, Georgia Colleluori, Rui Chen, Sanjay Mediwala, Clifford Qualls, Michael Liebschner, Dennis T Villareal, Reina Armamento-Villareal

Faculty, Staff and Students Publications

CONTEXT: Type 2 diabetes mellitus (T2D) is often accompanied by male hypogonadism and both conditions are associated with increased risk for fractures. Testosterone (T) has been shown to improve the bone health of hypogonadal men but has not been tested in patients who also have T2D in addition to low T. To date, there is no treatment that is specifically recommended for bone disease among patients with T2D. This study will evaluate the effect of T therapy on the bone health of male veterans with low T who also have T2D.

METHODS: This is a randomized double-blind placebo-controlled trial of …

Pegylated Arginine Deiminase Depletes Plasma Arginine But Maintains Tissue Arginine Availability In Young Pigs, Mahmoud A Mohammad, Inka C Didelija, Barbara Stoll, Trung C Nguyen, Juan C Marini

Faculty, Staff and Students Publications

Pegylated arginine deiminase (ADI-PEG20) results in the depletion of arginine with the production of isomolar amounts of citrulline. This citrulline has the potential to be utilized by the citrulline recycling pathway regenerating arginine and sustaining tissue arginine availability. The goal of this research was to test the hypothesis that ADI-PEG20 depletes circulating arginine in pigs but maintains tissue arginine concentration and function, and to characterize the kinetics of citrulline and arginine. Two multitracer approaches (bolus dose and primed-continuous infusion) were used to investigate the metabolism of arginine and citrulline in Control (

Tbx5-Encoded T-Box Transcription Factor 5 Variant T223m Is Associated With Long Qt Syndrome And Pediatric Sudden Cardiac Death, Alexandra M Markunas, Perathu K R Manivannan, Jordan E Ezekian, Agnim Agarwal, William Eisner, Katherina Alsina, Hugh D Allen, Gregory A Wray, Jeffrey J Kim, Xander H T Wehrens, Andrew P Landstrom

Faculty, Staff and Students Publications

Long QT syndrome (LQTS) is a genetic disease resulting in a prolonged QT interval on a resting electrocardiogram, predisposing affected individuals to polymorphic ventricular tachycardia and sudden death. Although a number of genes have been implicated in this disease, nearly one in four individuals exhibiting the LQTS phenotype are genotype-negative. Whole-exome sequencing identified a missense T223M variant in TBX5 that cosegregates with prolonged QT interval in a family with otherwise genotype-negative LQTS and sudden death. The TBX5-T223M variant was absent among large ostensibly healthy populations (gnomAD) and predicted to be pathogenic by in silico modeling based on Panther, PolyPhen-2, Provean, …

Hands-On Training About Overfitting, Janez Demšar, Blaž Zupan

Faculty, Staff and Students Publications

Overfitting is one of the critical problems in developing models by machine learning. With machine learning becoming an essential technology in computational biology, we must include training about overfitting in all courses that introduce this technology to students and practitioners. We here propose a hands-on training for overfitting that is suitable for introductory level courses and can be carried out on its own or embedded within any data science course. We use workflow-based design of machine learning pipelines, experimentation-based teaching, and hands-on approach that focuses on concepts rather than underlying mathematics. We here detail the data analysis workflows we use …

Inhibition Of Camkk2 Impairs Autophagy And Castration-Resistant Prostate Cancer Via Suppression Of Ampk-Ulk1 Signaling, Chenchu Lin, Alicia M Blessing, Thomas L Pulliam, Yan Shi, Sandi R Wilkenfeld, Jenny J Han, Mollianne M Murray, Alexander H Pham, Kevin Duong, Sonja N Brun, Reuben J Shaw, Michael M Ittmann, Daniel E Frigo

Faculty, Staff and Students Publications

Previous work has suggested androgen receptor (AR) signaling mediates prostate cancer progression in part through the modulation of autophagy. However, clinical trials testing autophagy inhibition using chloroquine derivatives in men with castration-resistant prostate cancer (CRPC) have yet to yield promising results, potentially due to the side effects of this class of compounds. We hypothesized that identification of the upstream activators of autophagy in prostate cancer could highlight alternative, context-dependent targets for blocking this important cellular process during disease progression. Here, we used molecular, genetic and pharmacological approaches to elucidate an AR-mediated autophagy cascade involving Ca2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2; …

Vulvar Lichen Sclerosus In Women Of Reproductive Age, Elysha Kolitz, Laura Gammon, Melissa Mauskar

Faculty, Staff and Students Publications

Vulvar lichen sclerosus (vLS) is an inflammatory skin condition that predominantly affects the vulvar and perianal regions. Approximately 50% of cases present prior to menopause; however, there is a paucity of data on vLS in women of reproductive age as well as during their pregnancies. A retrospective review was performed at two tertiary referral centers to better describe cases of vLS in women of reproductive age. Thirty-three patients with a mean age of 40 years met inclusion criteria. In this group, vulvar pruritus was the most common presenting symptom (52%); 61% had biopsy-proven vLS, 42% had at least one autoimmune …

A Prospective Surveillance Study On The Kinetics Of The Humoral Immune Response To The Respiratory Syncytial Virus Fusion Protein In Adults In Houston, Texas, Brittani N Blunck, Letisha Aideyan, Xunyan Ye, Vasanthi Avadhanula, Laura Ferlic-Stark, Lynn Zechiedrich, Brian E Gilbert, Pedro A Piedra

Faculty, Staff and Students Publications

Respiratory syncytial virus (RSV)-specific serum antibody has been correlated to protection of infection and reduction of severe disease, but reinfection is still frequent. In this study, we evaluated RSV-specific serum antibody activity following natural RSV re-infection to examine the longevity of the humoral immune response in adults. Nineteen healthy adult volunteers under sixty-five years of age were enrolled during the 2018-2019 RSV season in Houston, TX. Blood was collected at three study visits. The kinetics of RSV-neutralizing, RSV F site-specific competitive, and RSV-binding antibodies in serum samples were measured by microneutralization and enzyme-linked immunosorbent assays. Three distinct profiles of RSV-specific …

Continuous-Flow Left Ventricular Assist Device Therapy In Adults With Transposition Of The Great Vessels, Tadahisa Sugiura, Chitaru Kurihara, Masashi Kawabori, Andre C Critsinelis, Andrew B Civitello, Jeffrey A Morgan, O H Frazier

Faculty, Staff and Students Publications

An increasing number of children with congenital heart disease are surviving into adulthood and subsequently developing end-stage heart failure. Two example populations are adults who have been previously operated on for congenitally corrected transposition of the great arteries (CCTGA) and transposition of the great arteries (TGA). Implantation of a continuous flow left ventricular assist device (CF-LVAD) in these patients can present unusual anatomical and physiologic challenges. In this report, we describe outcomes of CF-LVAD implantation in three such patients. These cases demonstrate the feasibility of implanting a CF-LVAD in patients who have undergone surgery for CCTGA and/or TGA.

The Mitochondrial Protease Lonp1 Promotes Proteasome Inhibitor Resistance In Multiple Myeloma, Laure Maneix, Melanie A Sweeney, Sukyeong Lee, Polina Iakova, Shannon E Moree, Ergun Sahin, Premal Lulla, Sarvari V Yellapragada, Francis T F Tsai, Andre Catic

Faculty, Staff and Students Publications

Multiple myeloma and its precursor plasma cell dyscrasias affect 3% of the elderly population in the US. Proteasome inhibitors are an essential part of several standard drug combinations used to treat this incurable cancer. These drugs interfere with the main pathway of protein degradation and lead to the accumulation of damaged proteins inside cells. Despite promising initial responses, multiple myeloma cells eventually become drug resistant in most patients. The biology behind relapsed/refractory multiple myeloma is complex and poorly understood. Several studies provide evidence that in addition to the proteasome, mitochondrial proteases can also contribute to protein quality control outside of …

Mapk4 Promotes Prostate Cancer By Concerted Activation Of Androgen Receptor And Akt, Tao Shen, Wei Wang, Wolong Zhou, Ilsa Coleman, Qinbo Cai, Bingning Dong, Michael M Ittmann, Chad J Creighton, Yingnan Bian, Yanling Meng, David R Rowley, Peter S Nelson, David D Moore, Feng Yang

Faculty, Staff and Students Publications

Prostate cancer (PCa) is the second leading cause of cancer death in American men. Androgen receptor (AR) signaling is essential for PCa cell growth/survival and remains a key therapeutic target for lethal castration-resistant PCa (CRPC). GATA2 is a pioneer transcription factor crucial for inducing AR expression/activation. We recently reported that MAPK4, an atypical MAPK, promotes tumor progression via noncanonical activation of AKT. Here, we demonstrated that MAPK4 activated AR by enhancing GATA2 transcriptional expression and stabilizing GATA2 protein through repression of GATA2 ubiquitination/degradation. MAPK4 expression correlated with AR activation in human CRPC. Concerted activation of both GATA2/AR and AKT by …

Targeting Nsd2-Mediated Src-3 Liquid-Liquid Phase Separation Sensitizes Bortezomib Treatment In Multiple Myeloma, Jing Liu, Ying Xie, Jing Guo, Xin Li, Jingjing Wang, Hongmei Jiang, Ziyi Peng, Jingya Wang, Sheng Wang, Qian Li, Linquan Ye, Yuping Zhong, Qiguo Zhang, Xiaozhi Liu, David M Lonard, Jin Wang, Bert W O'Malley, Zhiqiang Liu

Faculty, Staff and Students Publications

Development of chemoresistance is the main reason for failure of clinical management of multiple myeloma (MM), but the genetic and epigenetic aberrations that interact to confer such chemoresistance remains unknown. In the present study, we find that high steroid receptor coactivator-3 (SRC-3) expression is correlated with relapse/refractory and poor outcomes in MM patients treated with bortezomib (BTZ)-based regimens. Furthermore, in immortalized cell lines, high SRC-3 enhances resistance to proteasome inhibitor (PI)-induced apoptosis. Overexpressed histone methyltransferase NSD2 in patients bearing a t(4;14) translocation or in BTZ-resistant MM cells coordinates elevated SRC-3 by enhancing its liquid-liquid phase separation to supranormally modify histone …

The Rac-Gef Tiam1 Promotes Dendrite And Synapse Stabilization Of Dentate Granule Cells And Restricts Hippocampal-Dependent Memory Functions, Jinxuan Cheng, Federico Scala, Francisco A Blanco, Sanyong Niu, Karen Firozi, Laura Keehan, Shalaka Mulherkar, Emmanouil Froudarakis, Lingyong Li, Joseph G Duman, Xiaolong Jiang, Kimberley F Tolias

Faculty, Staff and Students Publications

The dentate gyrus (DG) controls information flow into the hippocampus and is critical for learning, memory, pattern separation, and spatial coding, while DG dysfunction is associated with neuropsychiatric disorders. Despite its importance, the molecular mechanisms regulating DG neural circuit assembly and function remain unclear. Here, we identify the Rac-GEF Tiam1 as an important regulator of DG development and associated memory processes. In the hippocampus, Tiam1 is predominantly expressed in the DG throughout life. Global deletion of Tiam1 in male mice results in DG granule cells with simplified dendritic arbors, reduced dendritic spine density, and diminished excitatory synaptic transmission. Notably, DG …

Vertical Sleeve Gastrectomy Confers Metabolic Improvements By Reducing Intestinal Bile Acids And Lipid Absorption In Mice, Lili Ding, Eryun Zhang, Qiaoling Yang, Lihua Jin, Kyle M Sousa, Bingning Dong, Yangmeng Wang, Jui Tu, Xiaoxiao Ma, Jingyan Tian, Hongli Zhang, Zhipeng Fang, Ana Guan, Yixin Zhang, Zhengtao Wang, David D Moore, Li Yang, Wendong Huang

Faculty, Staff and Students Publications

Vertical sleeve gastrectomy (VSG) is a highly effective bariatric surgery that sustainably treats obesity and type 2 diabetes (T2D). However, the underlying mechanisms governing its metabolic benefits remain unclear. In this study, we have used four different genetically modified mouse lines to understand the link between bile acid circulation and metabolic effects of VSG. Instead of directly activating the nuclear bile acid receptor farnesoid X receptor (Fxr) in the liver or intestine, VSG reduces intestinal levels of bile acids, thereby decreasing fat absorption in the intestine. Given the rising popularity of bariatric surgeries to treat obesity and associated T2D, the …

Association Of Nt-Probnp, Blood Pressure, And Cardiovascular Events: The Aric Study, Aliza Hussain, Wensheng Sun, Anita Deswal, James A De Lemos, John W Mcevoy, Ron C Hoogeveen, Kunihiro Matsushita, David Aguilar, Biykem Bozkurt, Salim S Virani, Amil M Shah, Elizabeth Selvin, Chiadi Ndumule, Christie M Ballantyne, Vijay Nambi

Faculty, Staff and Students Publications

BACKGROUND: Although intensive blood pressure reduction has cardiovascular benefits, the absolute benefit is greater in those at higher cardiovascular disease (CVD) risk.

OBJECTIVES: This study examined whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) helps identify subjects at higher risk for CVD events across systolic blood pressure (SBP), diastolic blood pressure (DBP), or pulse pressure (PP) categories.

METHODS: Participants from the ARIC (Atherosclerosis Risk In Communities) study visit 4 (1996 to 98) were grouped according to SBP, DBP, or PP categories and further stratified by NT-proBNP categories. Cox regression models were used to estimate hazard ratios for incident CVD (coronary heart disease, …

Hermansky-Pudlak Syndrome-2 Alters Mitochondrial Homeostasis In The Alveolar Epithelium Of The Lung, Karina Cuevas-Mora, Willy Roque, Hoora Shaghaghi, Bernadette R Gochuico, Ivan O Rosas, Ross Summer, Freddy Romero

Faculty, Staff and Students Publications

BACKGROUND: Mitochondrial dysfunction has emerged as an important player in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a common cause of idiopathic interstitial lung disease in adults. Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder that causes a similar type of pulmonary fibrosis in younger adults, although the role of mitochondrial dysfunction in this condition is not understood.

METHODS: We performed a detailed characterization of mitochondrial structure and function in lung tissues and alveolar epithelial cells deficient in the adaptor protein complex 3 beta 1 (Ap3b1) subunit, the gene responsible for causing subtype 2 of HPS (HPS-2).

RESULTS: We …

Common Questions And Misconceptions About Creatine Supplementation: What Does The Scientific Evidence Really Show?, Jose Antonio, Darren G Candow, Scott C Forbes, Bruno Gualano, Andrew R Jagim, Richard B Kreider, Eric S Rawson, Abbie E Smith-Ryan, Trisha A Vandusseldorp, Darryn S Willoughby, Tim N Ziegenfuss

Faculty, Staff and Students Publications

Supplementing with creatine is very popular amongst athletes and exercising individuals for improving muscle mass, performance and recovery. Accumulating evidence also suggests that creatine supplementation produces a variety of beneficial effects in older and patient populations. Furthermore, evidence-based research shows that creatine supplementation is relatively well tolerated, especially at recommended dosages (i.e. 3-5 g/day or 0.1 g/kg of body mass/day). Although there are over 500 peer-refereed publications involving creatine supplementation, it is somewhat surprising that questions regarding the efficacy and safety of creatine still remain. These include, but are not limited to: 1. Does creatine lead to water retention? 2. …

Cryo-Electron Tomography Of Candida Glabrata Plasma Membrane Proteins, Cristina Jiménez-Ortigosa, Jennifer Jiang, Muyuan Chen, Xuyuan Kuang, Kelley R Healey, Paul Castellano, Nikpreet Boparai, Steven J Ludtke, David S Perlin, Wei Dai

Faculty, Staff and Students Publications

Fungal plasma membrane proteins have long been recognized as targets for the development of antifungal agents. Despite recent progress in experimental approaches and computational structural predictions, our knowledge of the structural dynamics and spatial distribution of these membrane proteins in the context of their native lipid environment remains limited. By applying cryo-electron tomography (cryoET) and subtomogram analysis, we aim to characterize the structural characteristics and spatial distribution of membrane proteins present in Candida glabrata plasma membranes. This study has resulted in the identification of the membrane-embedded structure of the fungal H+-ATPase, Pma1. Tomograms of the plasma membrane revealed that Pma1 …

Addressing Artificial Intelligence Bias In Retinal Diagnostics, Philippe Burlina, Neil Joshi, William Paul, Katia D Pacheco, Neil M Bressler

Faculty, Staff and Students Publications

PURPOSE: This study evaluated generative methods to potentially mitigate artificial intelligence (AI) bias when diagnosing diabetic retinopathy (DR) resulting from training data imbalance or domain generalization, which occurs when deep learning systems (DLSs) face concepts at test/inference time they were not initially trained on.

METHODS: The public domain Kaggle EyePACS dataset (88,692 fundi and 44,346 individuals, originally diverse for ethnicity) was modified by adding clinician-annotated labels and constructing an artificial scenario of data imbalance and domain generalization by disallowing training (but not testing) exemplars for images of retinas with DR warranting referral (DR-referable) from darker-skin individuals, who presumably have greater …

Efficacy And Safety Of The Mrna-1273 Sars-Cov-2 Vaccine, Lindsey R Baden, Hana M El Sahly, Brandon Essink, Karen Kotloff, Sharon Frey, Rick Novak, David Diemert, Stephen A Spector, Nadine Rouphael, C Buddy Creech, John Mcgettigan, Shishir Khetan, Nathan Segall, Joel Solis, Adam Brosz, Carlos Fierro, Howard Schwartz, Kathleen Neuzil, Larry Corey, Peter Gilbert, Holly Janes, Dean Follmann, Mary Marovich, John Mascola, Laura Polakowski, Julie Ledgerwood, Barney S Graham, Hamilton Bennett, Rolando Pajon, Conor Knightly, Brett Leav, Weiping Deng, Honghong Zhou, Shu Han, Melanie Ivarsson, Jacqueline Miller, Tal Zaks, Cove Study Group

Faculty, Staff and Students Publications

BACKGROUND: Vaccines are needed to prevent coronavirus disease 2019 (Covid-19) and to protect persons who are at high risk for complications. The mRNA-1273 vaccine is a lipid nanoparticle-encapsulated mRNA-based vaccine that encodes the prefusion stabilized full-length spike protein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Covid-19.

METHODS: This phase 3 randomized, observer-blinded, placebo-controlled trial was conducted at 99 centers across the United States. Persons at high risk for SARS-CoV-2 infection or its complications were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 μg) or placebo 28 days apart. …

Eosinophils Attenuate Hepatic Ischemia-Reperfusion Injury In Mice Through St2-Dependent Il-13 Production, Yaochun Wang, Yang Yang, Meng Wang, Shuhong Wang, Jong-Min Jeong, Long Xu, Yankai Wen, Christoph Emontzpohl, Constance Lynn Atkins, Kevin Duong, Nicolas F Moreno, Xiaoyi Yuan, David R Hall, Wasim Dar, Dechun Feng, Bin Gao, Yong Xu, Zoltan Czigany, Sean P Colgan, J Steve Bynon, Shizuo Akira, Jared M Brown, Holger K Eltzschig, Elizabeth A Jacobsen, Cynthia Ju

Faculty, Staff and Students Publications

Eosinophils are a myeloid cell subpopulation that mediates type 2 T helper cell immune responses. Unexpectedly, we identified a rapid accumulation of eosinophils in 22 human liver grafts after hepatic transplantation. In contrast, no eosinophils were detectable in healthy liver tissues before transplantation. Studies with two genetic mouse models of eosinophil deficiency and a mouse model of antibody-mediated eosinophil depletion revealed exacerbated liver injury after hepatic ischemia and reperfusion. Adoptive transfer of bone marrow-derived eosinophils normalized liver injury of eosinophil-deficient mice and reduced hepatic ischemia and reperfusion injury in wild-type mice. Mechanistic studies combining genetic and adoptive transfer approaches identified …

Lkb1 And Ampk Instruct Cone Nuclear Position To Modify Visual Function, Courtney A Burger, Nicholas E Albrecht, Danye Jiang, Justine H Liang, Ross A Poché, Melanie A Samuel

Faculty, Staff and Students Publications

Cone photoreceptors detect light and are responsible for color vision. These cells display a distinct polarized morphology where nuclei are precisely aligned in the apical retina. However, little is known about the mechanisms involved in cone nuclear positioning or the impact of this organization on retina function. We show that the serine/threonine kinase LKB1 and one of its substrates, AMPK, regulate cone nuclear positioning. In the absence of either molecule, cone nuclei are misplaced along the axon, resulting in altered nuclear lamination. LKB1 is required specifically in cones to mediate this process, and disruptions in nuclear alignment result in reduced …

Intestinal Stem Cell-Derived Enteroids From Morbidly Obese Patients Preserve Obesity-Related Phenotypes: Elevated Glucose Absorption And Gluconeogenesis, Nesrin M Hasan, Kelli F Johnson, Jianyi Yin, Nicholas W Baetz, Lea Fayad, Vadim Sherman, Sarah E Blutt, Mary K Estes, Vivek Kumbhari, Nicholas C Zachos, Olga Kovbasnjuk

Faculty, Staff and Students Publications

OBJECTIVE: The mechanisms behind the efficacy of bariatric surgery (BS) for treating obesity and type 2 diabetes, particularly with respect to the influence of the small bowel, remain poorly understood. In vitro and animal models are suboptimal with respect to their ability to replicate the human intestinal epithelium under conditions induced by obesity. Human enteroids have the potential to accelerate the development of less invasive anti-obesity therapeutics if they can recapitulate the pathophysiology of obesity. Our aim was to determine whether adult stem cell-derived enteroids preserve obesity-characteristic patient-specific abnormalities in carbohydrate absorption and metabolism.

METHODS: We established 24 enteroid lines …

Relation Of Magnetic Resonance Imaging Based Arterial Signal Enhancement To Markers Of Peripheral Artery Disease, Olga A Gimnich, Jonathan Holbrook, Tatiana Belousova, Christina M Short, Addison A Taylor, Vijay Nambi, Joel D Morrisett, Christie M Ballantyne, Jean Bismuth, Dipan J Shah, Gerd Brunner

Faculty, Staff and Students Publications

Peripheral artery disease (PAD) is associated with impaired lower extremity function. We hypothesized that contrast-enhanced magnetic resonance imaging (CE-MRI) based arterial signal enhancement (SE) measures are associated with markers of PAD. A total of 66 participants were enrolled, 10 were excluded due to incomplete data, resulting in 56 participants for the final analyses (36 PAD, 20 matched controls). MR imaging was performed postreactive hyperemia using bilateral thigh blood-pressure cuffs. First pass-perfusion images were acquired at the mid-calf region with a high-resolution saturation recovery gradient echo pulse sequence, and arterial SE was measured for the lower extremity arteries. As expected, peak …

Education Of Infectious Diseases Fellows During The Covid-19 Pandemic Crisis: Challenges And Opportunities, Lisa M Chirch, Wendy S Armstrong, Gayle P Balba, Prathit A Kulkarni, Constance A Benson, Victoria Konold, Vera P Luther, Obinna N Nnedu, Sarah Perloff, Raymund R Razonable, Wendy Stead, George R Thompson, Michael T Melia

Faculty, Staff and Students Publications

One of the many challenges that has befallen the Infectious Diseases and Graduate Medical Education communities during the coronavirus disease 2019 (COVID-19) pandemic is the maintenance of continued effective education and training of the future leaders of our field. With the remarkable speed and innovation that has characterized the responses to this pandemic, educators everywhere have adapted existing robust and safe learning environments to meet the needs of our learners. This paper will review distinct aspects of education and training of the Infectious Diseases fellows we believe the COVID-19 pandemic has impacted most, including mentoring, didactics, and wellness. We anticipate …

Cyclic Nucleotide Selectivity Of Protein Kinase G Isozymes, Choel Kim, Rajesh Sharma

Faculty, Staff and Students Publications

The intrinsic activity of the C-terminal catalytic (C) domain of cyclic guanosine monophosphate (cGMP)-dependent protein kinases (PKG) is inhibited by interactions with the N-terminal regulatory (R) domain. Selective binding of cGMP to cyclic nucleotide binding (CNB) domains within the R-domain disrupts the inhibitory R-C interaction, leading to the release and activation of the C-domain. Affinity measurements of mammalian and plasmodium PKG CNB domains reveal different degrees of cyclic nucleotide affinity and selectivity; the CNB domains adjacent to the C-domain are more cGMP selective and therefore critical for cGMP-dependent activation. Crystal structures of isolated CNB domains in the presence and absence …

Calcium Ions Trigger The Exposure Of Phosphatidylserine On The Surface Of Necrotic Cells, Yoshitaka Furuta, Omar Pena-Ramos, Zao Li, Lucia Chiao, Zheng Zhou

Faculty, Staff and Students Publications

Intracellular Ca2+ level is under strict regulation through calcium channels and storage pools including the endoplasmic reticulum (ER). Mutations in certain ion channel subunits, which cause mis-regulated Ca2+ influx, induce the excitotoxic necrosis of neurons. In the nematode Caenorhabditis elegans, dominant mutations in the DEG/ENaC sodium channel subunit MEC-4 induce six mechanosensory (touch) neurons to undergo excitotoxic necrosis. These necrotic neurons are subsequently engulfed and digested by neighboring hypodermal cells. We previously reported that necrotic touch neurons actively expose phosphatidylserine (PS), an "eat-me" signal, to attract engulfing cells. However, the upstream signal that triggers PS externalization remained elusive. Here we …

The Gut Microbiome Contributes To Blood-Brain Barrier Disruption In Spontaneously Hypertensive Stroke Prone Rats, James W Nelson, Sharon C Phillips, Bhanu P Ganesh, Joseph F Petrosino, David J Durgan, Robert M Bryan

Faculty, Staff and Students Publications

In recent years, it has become apparent that the gut microbiome can influence the functioning and pathological states of organs and systems throughout the body. In this study, we tested the hypothesis that the gut microbiome has a major role in the disruption of the blood-brain barrier (BBB) in the spontaneously hypertensive stroke prone rats (SHRSP), an animal model for hypertensive cerebral small vessel disease (CSVD). Loss of BBB is thought to be an early and initiating component to the full expression of CSVD in animal models and humans. To test this hypothesis, newly born SHRSP pups were placed with …